NASA astronomers conducting a monthly sweep of the night sky
to identify previously unknown asteroids and comets will be able
to double their coverage and the number of discoveries they make,
thanks to new, state-of-the-art computer and data analysis
hardware.

The new equipment was purchased with funds from NASA, which
recently doubled its resources for near-Earth object research.

The new real-time analysis system, which serves a fully
automated charged-couple device (CCD) camera and telescope atop
Mt. Haleakala, Maui, HI, is part of the Near-Earth Asteroid
Tracking (NEAT) project, based at NASA's Jet Propulsion
Laboratory, Pasadena, CA. The new system features four 300-
megahertz processors that will be devoted solely to the enormous
amount of data coming back from the NEAT telescope on a nightly
basis.

"This new system will speed up the processing of data and
allow us to analyze up to 40 gigabytes of data each night, or the
equivalent of nearly 70 CD-ROMs," said Dr. Steven Pravdo, NEAT
project manager at JPL. "We will be able to double the amount of
sky we search each night, which is currently 500 square degrees,
as well as the number of new asteroids and comets we find during
each monthly observation cycle."

Installed in 1995, the NEAT camera uses a very large, very
sensitive 4,096- by 4,096-pixel CCD chip. The camera is located
on a 1-meter-diameter (39-inch) telescope operated by the U.S.
Air Force and located at an elevation of 3,000 meters (nearly 2
miles) above the Pacific Ocean. With stable climate, clear, dry
air and little light pollution, the NEAT tracking system has been
highly successful and continues to operate six days out of each
month. With additional support, the project hopes to increase
this six-day observational run to 18 nights of observations each
month.

Asteroids are considered relics of the formation of the
early solar system. Most of them are rocky materials, with some
composed of nickel and iron. Most range in size from boulders up
to the largest main belt asteroid, Ceres, which is approximately
965 kilometers (600 miles) in diameter. Comets, on the other
hand, are bodies of ice with embedded rock and organic materials
which heat up and become active, spewing gases and dust as they
approach the Sun.

The NEAT telescope detects these small bodies by observing
the same part of the sky three times during an interval of about
one hour and comparing the three images to determine the location
of objects moving across the sky. Since its inception, this
fully automated system has detected more than 25,000 objects,
including 30 near-Earth asteroids, two long-period comets and the
unique 1996 PW, which has the most eccentric orbit of all objects
discovered to date. More information about NEAT discoveries,
along with black-and-white images of the objects, is available at
http://huey.jpl.nasa.gov/~spravdo/neat.html .

Most recently, the NEAT team has discovered two new Earth-
crossing asteroids. One, designated 1998 HT31, is a relatively
small Apollo-type asteroid 270 meters (800 feet) in diameter; the
other, 1998HD14, is the 30th Aten to be discovered since JPL
astronomer Eleanor Helin first identified this class of asteroid
22 years ago, and the fifth discovered with the NEAT tracking
system. Both are classified as potentially hazardous asteroids
because their orbits come within 5 million kilometers (3 million
miles) of Earth, or about 20 times the distance of the Moon.
However, neither currently poses a threat to Earth.

"Atens are a rare class of asteroid because of their small
orbits, which are smaller than that of Earth's, and which never
allow them to wander far from our planet," said Helin, who is the
principal investigator of the NEAT program. "1998 HD14 passed
within 5 million kilometers (3 million miles of Earth) just a
week after we discovered it on April 29. This is relatively
close but poses no threat in the foreseeable future. Atens are
of particular interest to us because they stay so close to
Earth's orbit."

Along with near-Earth asteroids, astronomers are also
interested in tracking long-period comets, which travel vast
distances from the Oort Cloud, a region far beyond Pluto's orbit,
which is believed to house trillions of incipient comets. These
objects travel in very long paths through the solar system, and
can appear unannounced, with no calling cards.

"We are particularly interested in these comets because they
give us little time before appearing in Earth's vicinity," Helin
said.

Astronomers dedicated to discovering and tracking near-Earth
objects are eager to find all of the potentially dangerous
asteroids and comets long before they are likely to approach
Earth. For instance, the NEAT team at JPL is developing two new
CCD cameras and hopes to install them at Mt. Haleakala or other
facilities.

"With additional telescopes, longer observational runs and
our new operating system, we will be able to detect 90 percent of
the Earth-crossing asteroids that are larger than 1 kilometer
(6/10ths of a mile) in diameter in the next 10 years," Pravdo
said. "As our knowledge about these objects grows, we will be
able to provide better information which can be used in studies
of ways to divert Earth-crossers on threatening orbits toward
Earth."

NEAT was built and is being managed by the Jet Propulsion
Laboratory for NASA's Office of Space Science, Washington, DC.
JPL is a division of the California Institute of Technology in
Pasadena, CA.